Astra G/Mk4 - Coolant Query!

[Vaux-Man-G]

Quick one for you chaps,

We got a Mk4 1.6 LS 8v on an 02-reg.

Its using water, but not loads, every couple of weeks it goes down just below the seam, then I fill to just over and then it goes down again when I next check.

Im not getting mayo, apart from when the car has done really short journey's over a week (misses uses it to drop the lad at nursery). When I drive it on a weekend I usually use it for a good 15-20 miles and do give it some welly just to clear any crud, etc, and after the oil cap and rocker cover is clean as a whistle, no mayo, just normal oil-not even wattery).

The car isnt dripping water anywhere, nor is there any water in any of the internal footwell's.

My question is, is this normal for it to be using that much so often, or is it going somewhere and is there an underlying issue?

Any feedback would be great.

Oh and its not overheating, temp working perfect, going up and down as it should.

Thanks.

[John LE]

TBH you shouldn't be using any water, have the timing belt and water pump been done? I'd be checking that the water pump isn't leaking

[Vaux-Man-G]

TBH you shouldn't be using any water, have the timing belt and water pump been done? I'd be checking that the water pump isn't leaking

Yes they have both been done just before I bought it.

[John LE]

Double check the pump isn't leaking, if the rubber o ring hasn't seated right then you'll get a leak

[Exclusive BV]

Check the seams on the expansion bottle. These have been known to leak fluid under pressure when the engine is hot.

There could even be a hairline crack in it somewhere which is watertight when cool but leaks under pressure.